scholarly journals Effects of Ozone Oxidative Preconditioning on TNF-αRelease and Antioxidant-Prooxidant Intracellular Balance in Mice During Endotoxic Shock

2005 ◽  
Vol 2005 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Zullyt B. Zamora ◽  
Aluet Borrego ◽  
Orlay Y. López ◽  
René Delgado ◽  
Ricardo González ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Enzymatic Activity ◽  
Redox State ◽  
Endotoxic Shock ◽  
Gaseous Mixture ◽  
Hepatic Tissue ◽  
Mouse Serum ◽  
Antioxidant Systems ◽  
Dependent Manner

Ozone oxidative preconditioning is a prophylactic approach, which favors the antioxidant-prooxidant balance for preservation of cell redox state by the increase of antioxidant endogenous systems in both in vivo and in vitro experimental models. Our aim is to analyze the effect of ozone oxidative preconditioning on serum TNF-αlevels and as a modulator of oxidative stress on hepatic tissue in entodoxic shock model (mice treated with lipopolysaccharide (LPS)). Ozone/oxygen gaseous mixture which was administered intraperitoneally (0.2,0.4, and1.2mg/kg) once daily for five days before LPS (0.1mg/kg, intraperitoneal). TNF-αwas measured by cytotoxicity on L-929 cells. Biochemical parameters such as thiobarbituric acid reactive substances (TBARS), enzymatic activity of catalase, glutathione peroxidase, and glutathione-S transferase were measured in hepatic tissue. One hour after LPS injection there was a significant increase in TNF-αlevels in mouse serum. Ozone/oxygen gaseous mixture reduced serum TNF-αlevels in a dose-dependent manner. Statistically significant decreases in TNF-αlevels after LPS injection were observed in mice pretreated with ozone intraperitoneal applications at0.2(78%),0.4(98%), and1.2(99%). Also a significant increase in TBARS content was observed in the hepatic tissue of LPS-treated mice, whereas enzymatic activity of glutathion-S transferase and glutathione peroxidase was decreased. However in ozone-treated animals a significant decrease in TBARS content was appreciated as well as an increase in the activity of antioxidant enzymes. These results indicate that ozone oxidative preconditioning exerts inhibitory effects on TNF-αproduction and on the other hand it exerts influence on the antioxidant-prooxidant balance for preservation of cell redox state by the increase of endogenous antioxidant systems.

scholarly journals Mutant IDH1 Differently Affects Redox State and Metabolism in Glial Cells of Normal and Tumor Origin

Cancers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2028 ◽  
Author(s):  
Julia Biedermann ◽  
Matthias Preussler ◽  
Marina Conde ◽  
Mirko Peitzsch ◽  
Susan Richter ◽  
...  
Keyword(s):  
Redox State ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Idh1 Mutation ◽  
The Cancer Genome Atlas ◽  
Low Grade ◽  
Dependent Manner ◽  
Glioblastoma Cells ◽  
Isocitrate Dehydrogenase 1 ◽  
Nicotinamide Phosphoribosyltransferase

IDH1R132H (isocitrate dehydrogenase 1) mutations play a key role in the development of low-grade gliomas. IDH1wt converts isocitrate to α-ketoglutarate while reducing nicotinamide adenine dinucleotide phosphate (NADP+), whereas IDH1R132H uses α-ketoglutarate and NADPH to generate the oncometabolite 2-hydroxyglutarate (2-HG). While the effects of 2-HG have been the subject of intense research, the 2-HG independent effects of IDH1R132H are still ambiguous. The present study demonstrates that IDH1R132H expression but not 2-HG alone leads to significantly decreased tricarboxylic acid (TCA) cycle metabolites, reduced proliferation, and enhanced sensitivity to irradiation in both glioblastoma cells and astrocytes in vitro. Glioblastoma cells, but not astrocytes, showed decreased NADPH and NAD+ levels upon IDH1R132H transduction. However, in astrocytes IDH1R132H led to elevated expression of the NAD-synthesizing enzyme nicotinamide phosphoribosyltransferase (NAMPT). These effects were not 2-HG mediated. This suggests that IDH1R132H cells utilize NAD+ to restore NADP pools, which only astrocytes could compensate via induction of NAMPT. We found that the expression of NAMPT is lower in patient-derived IDH1-mutant glioma cells and xenografts compared to IDH1-wildtype models. The Cancer Genome Atlas (TCGA) data analysis confirmed lower NAMPT expression in IDH1-mutant versus IDH1-wildtype gliomas. We show that the IDH1 mutation directly affects the energy homeostasis and redox state in a cell-type dependent manner. Targeting the impairments in metabolism and redox state might open up new avenues for treating IDH1-mutant gliomas.

Biochemical aspects of the interaction of ethanol with barbiturates

1970 ◽  
Vol 48 (6) ◽  
pp. 706-711 ◽  
Author(s):  
H. Locksley Trenholm ◽  
William B. Maxwell ◽  
Charles J. Paul ◽  
G. Stuart Wiberg ◽  
Blake B. Coldwell
Keyword(s):  
Alcohol Dehydrogenase ◽  
Enzymatic Activity ◽  
Ammonium Sulfate ◽  
Hepatic Tissue ◽  
Alcohol Metabolism ◽  
Ammonium Sulfate Precipitation ◽  
Tissue Slices ◽  
Catalyzed Oxidation ◽  
Oxidation Of Ethanol

When pentobarbital is added to a hepatic supernatant enzyme fraction which contains alcohol dehydrogenase from a rat, the rates of the enzyme-catalyzed oxidation of ethanol and reduction of acetaldehyde are increased. The pentobarbital enhancement of enzymatic activity which is dependent on pentobarbital concentration is still observed when the enzyme is purified by column chromatography on DEAE- and CM-Sephadex and ammonium sulfate precipitation. In in vitro studies where hepatic tissue slices were incubated with alcohol, pentobarbital inhibited the metabolism of alcohol and increased the acetaldehyde levels in the incubation mixture. The addition of 32.5 mM NAD resulted in a return of alcohol metabolism and acetaldehyde concentrations to control levels.

Role of individual phosphorylation sites for the 14-3-3-protein-dependent activation of yeast neutral trehalase Nth1

2012 ◽  
Vol 443 (3) ◽  
pp. 663-670 ◽  
Author(s):  
Dana Veisova ◽  
Eva Macakova ◽  
Lenka Rezabkova ◽  
Miroslav Sulc ◽  
Petr Vacha ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Limited Proteolysis ◽  
Terminal Segment ◽  
Protein Isoforms ◽  
Stable Complex ◽  
Phosphorylation Sites ◽  
Dependent Manner ◽  
Neutral Trehalase ◽  
Activity Measurements

Trehalases are important highly conserved enzymes found in a wide variety of organisms and are responsible for the hydrolysis of trehalose that serves as a carbon and energy source as well as a universal stress protectant. Emerging evidence indicates that the enzymatic activity of the neutral trehalase Nth1 in yeast is enhanced by 14-3-3 protein binding in a phosphorylation-dependent manner through an unknown mechanism. In the present study, we investigated in detail the interaction between Saccharomyces cerevisiae Nth1 and 14-3-3 protein isoforms Bmh1 and Bmh2. We determined four residues that are phosphorylated by PKA (protein kinase A) in vitro within the disordered N-terminal segment of Nth1. Sedimentation analysis and enzyme kinetics measurements show that both yeast 14-3-3 isoforms form a stable complex with phosphorylated Nth1 and significantly enhance its enzymatic activity. The 14-3-3-dependent activation of Nth1 is significantly more potent compared with Ca2+-dependent activation. Limited proteolysis confirmed that the 14-3-3 proteins interact with the N-terminal segment of Nth1 where all phosphorylation sites are located. Site-directed mutagenesis in conjunction with the enzyme activity measurements in vitro and the activation studies of mutant forms in vivo suggest that Ser60 and Ser83 are sites primarily responsible for PKA-dependent and 14-3-3-mediated activation of Nth1.

scholarly journals Protective Effects of a Human 18-Kilodalton Cationic Antimicrobial Protein (CAP18)-Derived Peptide against Murine Endotoxemia

1998 ◽  
Vol 66 (5) ◽  
pp. 1861-1868 ◽  
Author(s):  
Teruo Kirikae ◽  
Michimasa Hirata ◽  
Hiromi Yamasu ◽  
Fumiko Kirikae ◽  
Hiroshi Tamura ◽  
...  
Keyword(s):  
Endotoxic Shock ◽  
Endotoxin Shock ◽  
Antimicrobial Protein ◽  
Dependent Manner ◽  
Protective Effects ◽  
Amino Acid Peptide ◽  
Dose Dependent ◽  
Necrosis Factor ◽  
Lps Binding

ABSTRACT CAP18 (an 18-kDa cationic antimicrobial protein) is a granulocyte-derived protein that can bind lipopolysaccharide (LPS) and inhibit various activities of LPS in vitro. The present study examined the protective effect of a synthetic 27-amino-acid peptide (CAP18109–135) from the LPS-binding domain of CAP18 against antibiotic-induced endotoxin shock, using highly LPS-sensitived-(+)-galactosamine (d-GalN)-sensitized C3H/HeN mice. The antibiotic-induced endotoxin (CAZ-endotoxin) was prepared from the culture filtrate of Pseudomonas aeruginosa PAO1 exposed to ceftazidime (CAZ). Injection of CAP18109–135protected the mice injected with LPS or CAZ-endotoxin from death and lowered their tumor necrosis factor (TNF) levels in serum in a dose-dependent manner. Treatment with CAZ caused death of thed-GalN-sensitized P. aeruginosa PAO-infected mice within 48 h, while injection with CAP18109–135rescued the mice from death. In the mice rescued from death by injection with CAP18109–135, endotoxin levels in plasma and TNF production by liver tissues were decreased but the numbers of viable infecting bacteria in their blood were not decreased significantly and remained at the levels in CAZ-treated mice. These results indicate that CAP18109–135 is capable of preventing antibiotic-induced endotoxic shock in mice with septicemia and that the effect is due to its LPS-neutralizing activity rather than to its antibacterial activity.

scholarly journals Induction of Glutathione Peroxidase 4 Expression during Enterocytic Cell Differentiation

2011 ◽  
Vol 286 (12) ◽  
pp. 10764-10772 ◽  
Author(s):  
Bodo Speckmann ◽  
Hans-Jürgen Bidmon ◽  
Antonio Pinto ◽  
Martin Anlauf ◽  
Helmut Sies ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Promoter Activity ◽  
Tissue Cell ◽  
Dependent Manner ◽  
Direct Role ◽  
Intestinal Epithelia ◽  
Protein Levels ◽  
Enterocytic Differentiation

Glutathione peroxidase 4 (GPx4), an abundant selenoenzyme, is ubiquitously expressed in a tissue-, cell- and differentiation-dependent manner, and it is localized in cytoplasmic, mitochondrial, and nuclear cellular compartments. Here, we report cytoplasmic and nuclear localization of GPx4 in Caco-2 intestinal epithelial cells. Enterocytic differentiation of Caco-2 cells triggers an increase in GPx4 mRNA and protein levels, mediated by enhanced promoter activity. We identified a combined cAMP response element (CREB) and CCAAT/enhancer binding protein (C/EBP) site as critical for the differentiation-triggered GPx4 promoter activity. Induction of GPx4 correlated with C/EBPα transcript levels during differentiation, suggesting a role of C/EBPα as regulator of enterocytic GPx4 expression. Consistent with the in vitro results, GPx4 protein was detected in cytoplasmic and nuclear compartments of enterocytes in human intestinal epithelia. GPx4 is uniformly expressed in colonic crypts and is differentially expressed along the crypt-to-villus axis in the small intestine with a more pronounced expression of GPx4 in the upper villi, which contain fully differentiated enterocytes. These data suggest that intestinal GPx4 expression is modulated by the enterocytic differentiation program, and the results support a direct role of nuclear GPx4 in the (selenium-dependent) prevention of oxidative damage in the gastrointestinal tract.

scholarly journals Ca2+-dependent redox modulation of SERCA 2b by ERp57

2003 ◽  
Vol 164 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Yun Li ◽  
Patricia Camacho
Keyword(s):  
Redox State ◽  
Dynamic Control ◽  
Specific Interaction ◽  
Calcium Atpase ◽  
Dependent Manner ◽  
Terminal Sequence ◽  
Redox Modulation ◽  
Serca 2A ◽  
Er Calcium

We demonstrated previously that calreticulin (CRT) interacts with the lumenal COOH-terminal sequence of sarco endoplasmic reticulum (ER) calcium ATPase (SERCA) 2b to inhibit Ca2+ oscillations. Work from other laboratories demonstrated that CRT also interacts with the ER oxidoreductase, ER protein 57 (also known as ER-60, GRP58; ERp57) during folding of nascent glycoproteins. In this paper, we demonstrate that ERp57 overexpression reduces the frequency of Ca2+ oscillations enhanced by SERCA 2b. In contrast, overexpression of SERCA 2b mutants defective in cysteines located in intralumenal loop 4 (L4) increase Ca2+ oscillation frequency. In vitro, we demonstrate a Ca2+-dependent and -specific interaction between ERp57 and L4. Interestingly, ERp57 does not affect the activity of SERCA 2a or SERCA 2b mutants lacking the CRT binding site. Overexpression of CRT domains that disrupt the interaction of CRT with ERp57 behave as dominant negatives in the Ca2+ oscillation assay. Our results suggest that ERp57 modulates the redox state of ER facing thiols in SERCA 2b in a Ca2+-dependent manner, providing dynamic control of ER Ca2+ homeostasis.

scholarly journals Thymoquinone Inhibits Growth of Acute Myeloid Leukemia Cells through Reversal SHP-1 and SOCS-3 Hypermethylation: In Vitro and In Silico Evaluation

2021 ◽  
Vol 14 (12) ◽  
pp. 1287
Author(s):  
Futoon Abedrabbu Al-Rawashde ◽  
Muhammad Farid Johan ◽  
Wan Rohani Wan Taib ◽  
Imilia Ismail ◽  
Syed Ahmad Tajudin Tuan Johari ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Myeloid Leukemia ◽  
Enzymatic Activity ◽  
Myeloid Leukemia ◽  
Nigella Sativa ◽  
Dependent Manner ◽  
Cancer Pathogenesis ◽  
Stat Signaling ◽  
Acute Myeloid

Epigenetic silencing of tumor suppressor genes (TSGs) plays an essential role in cancer pathogenesis, including acute myeloid leukemia (AML). All of SHP-1, SOCS-1, and SOCS-3 are TSGs that negatively regulate JAK/STAT signaling. Enhanced re-expression of TSGs through de-methylation represents a therapeutic target in several cancers. Thymoquinone (TQ) is a major component of Nigella sativa seeds with anticancer effects against several cancers. However, the effects of TQ on DNA methylation are not entirely understood. This study aimed to evaluate the ability of TQ to re-express SHP-1, SOCS-1, and SOCS-3 in MV4-11 AML cells through de-methylation. Cytotoxicity, apoptosis, and cell cycle assays were performed using WSTs-8 kit, Annexin V-FITC/PI apoptosis detection kit, and fluorometric-red cell cycle assay kit, respectively. The methylation of SHP-1, SOCS-1, and SOCS-3 was evaluated by pyrosequencing analysis. The expression of SHP-1, SOCS-1, SOCS-3, JAK2, STAT3, STAT5A, STAT5B, FLT3-ITD, DNMT1, DNMT3A, DNMT3B, TET2, and WT1 was assessed by RT-qPCR. The molecular docking of TQ to JAK2, STAT 3, and STAT5 was evaluated. The results revealed that TQ significantly inhibited the growth of MV4-11 cells and induced apoptosis in a dose- and time-dependent manner. Interestingly, the results showed that TQ binds the active pocket of JAK2, STAT3, and STAT5 to inhibit their enzymatic activity and significantly enhances the re-expression of SHP-1 and SOCS-3 through de-methylation. In conclusion, TQ curbs MV4-11 cells by inhibiting the enzymatic activity of JAK/STAT signaling through hypomethylation and re-expression of JAK/STAT negative regulators and could be a promising therapeutic candidate for AML patients.

scholarly journals Bisphenol A and S, but Not F, Alter Oxidative Stress Levels in Spermatozoa

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A483-A484
Author(s):  
Mimi Nguyen ◽  
Reem Sabry ◽  
., Elizabeth J St. John ◽  
Laura A Favetta
Keyword(s):  
Oxidative Stress ◽  
Glutathione Peroxidase ◽  
Bisphenol A ◽  
Sperm Quality ◽  
Gradient Centrifugation ◽  
Endocrine Disrupting Compounds ◽  
Dependent Manner ◽  
Stress Levels ◽  
Relevant Dose

Abstract Exposures to endocrine disrupting compounds (EDCs) have been linked to male reproductive dysfunction. The increase in prevalence of male infertility to date has been correlated with the widespread use of bisphenols, particularly bisphenol A and its analogs. Current literature suggests that exposure to EDCs is associated with abnormalities in spermatogenesis, as well as reduced sperm motility and morphology. At this time, the mechanism for bisphenols’ action in spermatozoa is still unknown, though it has been proposed that bisphenols alter sperm parameters by affecting their oxidative stress pathways. The aim of this project is to elucidate whether BPA and its analogs affect oxidative stress levels inducing decreased sperm quality and fertilization capability. An in vitro bovine model was used as the most appropriate translational model to humans. Motile spermatozoa were separated using Percoll gradient centrifugation of frozen-thawed sperm and a pilot experiment was conducted in a time-dependent manner to establish the ideal incubation time of 4 hours. Sperm was then incubated in five treatment groups: control, vehicle (0.01% ethanol), BPA, BPS, and BPF, at the physiological relevant dose of 0.05 mg/ml in 0.01% ethanol. Key reactive oxygen species (ROS) scavenger genes (superoxide mutase 1 [SOD1], superoxide mutase 2 [SOD2], catalase [CAT], glutathione peroxidase 1 [GPX1], glutathione peroxidase 4 [GPX4]) were quantified at the RNA level using qPCR. Of the five genes examined: BPA, BPS, and BPF exposure significantly decreased GPX4 expression (p<0.05) compared to control and vehicle groups. BPA and BPS exposure significantly increased SOD1 expression compared to BPF, control, and vehicle (p<0.05). No significant differences were found in GPX1 after bisphenols’ exposure. SOD2 and CAT expression was not detectable in all five groups suggesting a lack of expression in bovine sperm. Future investigations will involve experiments at the protein level and quantifying total ROS levels. Additionally, sperm morphology was evaluated using Spermac stain. Preliminary results indicate an increased number of abnormal spermatozoa with notably tail defects after 4 hours of bisphenols exposure. These initial findings support BPA and BPS’s ability to alter oxidative stress pathways in sperm via changes in antioxidant enzymes but suggest that BPF likely acts through different mechanisms. Overall, this research aims to understand the effects of bisphenols on male fertility to improve male factors during assisted reproductive biotechnologies.

scholarly journals Vitamin C Is a Kinase Inhibitor: Dehydroascorbic Acid Inhibits IκBα Kinase β

2004 ◽  
Vol 24 (15) ◽  
pp. 6645-6652 ◽  
Author(s):  
Juan M. Cárcamo ◽  
Alicia Pedraza ◽  
Oriana Bórquez-Ojeda ◽  
Bing Zhang ◽  
Roberto Sanchez ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Vitamin C ◽  
Enzymatic Activity ◽  
Redox State ◽  
Kinase Inhibitor ◽  
Dehydroascorbic Acid ◽  
Molecular Action ◽  
Cellular Signal ◽  
Direct Linkage

ABSTRACT Reactive oxygen species (ROS) are key intermediates in cellular signal transduction pathways whose function may be counterbalanced by antioxidants. Acting as an antioxidant, ascorbic acid (AA) donates two electrons and becomes oxidized to dehydroascorbic acid (DHA). We discovered that DHA directly inhibits IκBα kinase β (IKKβ) and IKKα enzymatic activity in vitro, whereas AA did not have this effect. When cells were loaded with AA and induced to generate DHA by oxidative stress in cells expressing a constitutive active IKKβ, NF-κB activation was inhibited. Our results identify a dual molecular action of vitamin C in signal transduction and provide a direct linkage between the redox state of vitamin C and NF-κB signaling events. AA quenches ROS intermediates involved in the activation of NF-κB and is oxidized to DHA, which directly inhibits IKKβ and IKKα enzymatic activity. These findings define a function for vitamin C in signal transduction other than as an antioxidant and mechanistically illuminate how vitamin C down-modulates NF-κB signaling.

Release of Type II phospholipase A2 immunoreactivity and phospholipase A2 enzymatic activity from human placenta

1997 ◽  
Vol 153 (1) ◽  
pp. 151-157 ◽  
Author(s):  
W Farrugia ◽  
G E Rice ◽  
M H Wong ◽  
K F Scott ◽  
S P Brennecke
Keyword(s):  
Enzyme Activity ◽  
Enzymatic Activity ◽  
Phospholipase A2 ◽  
Incubation Medium ◽  
Placental Tissue ◽  
Dependent Manner ◽  
Type Ii ◽  
Intracellular Enzyme ◽  
Human Placental Tissue

Abstract The aim of this study was to determine whether Type II phospholipase A2 (PLA2) is released from late pregnant human placental tissue. Placental explants were incubated in vitro and the release of immunoreactive (ir) Type II PLA2 and PLA2 enzymatic activity into the medium was determined. Both irType II PLA2 and PLA2 enzymatic activity accumulated in the incubation medium in a time-dependent manner (P<0·0001). This release was not associated with a loss of cell membrane integrity, as indicated by measurement of the intracellular enzyme, lactate dehydrogenase, in the incubation medium. The concentration of irType II PLA2 and PLA2 enzyme activity present in incubation medium were significantly correlated (P<0·01). Consistent with the hypothesis that Type II PLA2 may be stored in secretory granules within human placental tissue, incubation in the presence of a membrane depolarising concentration of KCl (60 mm) caused the release of irType II PLA2 2·0-fold (P<0·001). PLA2 enzyme activity released into the incubation medium displays biochemical characteristics consistent with those previously reported for secretory PLA2 isozymes, that is, a requirement for millimolar concentrations of calcium for optimal enzyme activity, inhibited by reducing agents, such as dithiothreitol and insensitive to heat inactivation. The data obtained in this study establish that irType II PLA2 is released from term placenta, when incubated in vitro. The release of this extracellularly-active PLA2 isozyme may contribute to gestational and labour-associated increases in glycerophospholipid metabolism and prostaglandin formation. Journal of Endocrinology (1997) 153, 151–157

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